The multiplicity and catalytic nature of the collection of oxidative enzymes or function monoxygenases known collectively as cytochrome P-450 will be studied using the anticoagulants warfarin and phenprocoumon as structural and stereochemical probes of the system. Three major questions will be investigated: 1) can changes in the ratios of multiple products produced from a given substrate be used as a tool to gain information regarding both the multiplicity and nature of these enzymes (product ratio method). In these studies the ratios of the multiple oxidative products formed from the substrates by purified enzymes, mixtures of purified enzymes and microsomes will be determined. 2) The mechanism of aromatic hydroxylation catalyzed by these enzymes will be studied using selectively deuterated substrates (warfarin, phenprocoumon and 3) the active site of the specific forms of cytochrome P-450 inducible by beta-napthoflavone will be probed using analogs of warfarin and phenprocoumon in which the configurations and preferred solution conformations of these substances are known. Prediction of metabolic profiles based on model active sites will be advanced and tested experimentally.